I have an 05 C6 with the power roof. All of a sudden it has developed the following problem: The roof starts to open properly but when the rear of the roof tips up and the trunk cover opens before the roof can go into the well the trunk cover starts to fall jamming the process. The only way to clear it up is to release the pressure at the pump and work the roof manually. There seem to be no leaks and the reservoir is properly filled. Could it be a relay somewhere? Does anyone have any thoughts? Thanks!

 

Is the tonneau cover falling under hydralic power or gravity?

If under power....Check the location and alignment of all the switches. Could be the tonneau thinks the roof has entered its storage compartment and it starts to close...hence switch location/alignment.

Don't think this is a relay or fuse issue.

If gravity...there is a leak.

 

Yes, It is comming down under power and causes a jam that has to be relieved by releasing pressure at the pump. Any thoughts on where I can find those sensors? Thanks!

 

2005 service manual pg 8-581 shows 13 actuators.
As a lead you might look toward the front on top of the carpet of the drivers rear wheel well. That specific switch is called the Tonneau Open Switch. The Tonneau Pull Down Switch and a computer called the Folding Top Module best I can tell from the manual are both behind the water fall. A code may have been set to aid in diagnosis.
Good hunting.

 

Thanks! I will take a look

 

Folding Top Control Module

The folding top control (FTC) module when commanded controls the opening and closing of the power folding top through input information from folding top position switches, top limit switches and class 2 messages from the door control modules and body control module. The FTC module is capable of determining the state of all moving components of the folding top system at any time during an open or close operation. Also through input information, the module can make corrections in the position of components when necessary while continuing in the direction indicated by the folding top control switch.
The FTC module can stop operation or reverse direction during any point of operation when you change the direction of the control switch. To avoid an inadvertent operation of the folding top system when the top is fully open or closed, a 0.75 second delay occurs after the activation of the control switch before the FTC module activates the pump motor and the valves. When the system is activated from a suspended state, the response time is less than 60 ms.



Folding Top Cover Latch Actuator

The power folding top system includes a folding top cover that is powered open and close by a hydraulic system that is controlled by the FTC module. A power unlatch motor is used to unlatch the folding top cover before the folding top control (FTC) module powers the top cover open. The folding top cover unlatching is requested by the FTC module via class 2 message, but is executed by the body control module (BCM). When requested, the BCM applies battery voltage through the folding top cover release relay control circuit to the tonneau release relay. The relay is energized and battery voltage is applied through the folding top cover release control circuit to the latch actuator. The actuator is energized and the latch releases the folding top cover.



Folding Top Cover Pull Down Actuator

The purpose of the folding top cover pull down actuator is to compress the folding top when its in the down position while the cover is being closed.
Battery positive voltage is supplied at all times to the folding top cover pull down actuator from the TONNEAU RELEASE Fuse located in the BCM fuse block. The pull down actuator is also provided with a control circuit, an ajar status circuit, and a ground circuit.
After the folding top cover latch actuator releases the cover, an internal switch in the actuator opens the control circuit to the pull down actuator commanding it to raise the striker. The pull down actuator will turn itself off once the striker is fully extended. Then with the striker in the extended position, the folding top cover pull down ajar signal circuit is pulled low signaling the BCM the ajar status of the pull down actuator. After the folding top is in the desired position, and the folding top cover is closed and latched, the internal switch in the latch actuator closes pulling the control circuit of the pull down actuator to ground, commanding it to retract the striker. The pull down actuator then reverses polarity of its motor to retract the striker in order to finish closing the cover.



Folding Top Position or Limit Switches

The power folding top system uses seven different position or limit switches that provide input information to the folding top control (FTC) module. The FTC module uses this input information to determine the state and position of the folding top components. When the switches are closed, battery voltage is applied through the switch signal circuit to the FTC module indicating the position of the component. The following is a list of the position switches and their defined state with the power folding top in the CLOSED position:



System Operation

Before any movement of the power folding top is allowed, the folding top control (FTC) module must be aware of the following conditions:
The sequence for opening the folding top is as follows:

1. Manually unlatch the header. The FTC module reads the pin receiver switch is Inactive.
2. Hold the open/close control switch to the OPEN request position.
3. The folding top status changes to opening.
4. A message is sent to disable the windows from operating using the door switches.
5. The windows open using the express open mode.
6. The 1 bow and 5 bow are raised.
7. A message is sent to the body control module (BCM) to unlatch the folding top cover.
8. The BCM sends folding top cover latch ajar message via class 2 serial data line.
9. The folding top cover opens.
10. The folding top cover pull down striker is extended.
11. The BCM sends folding top cover pull down ajar message via class 2 serial data line.
12. The top retracts to the open position and is stowed in the rear compartment.
13. The folding top cover closes.
14. The BCM sends folding top cover latch not ajar message via class 2 serial data line.
15. The windows are enabled and an audible chime is heard.
16. The folding top cover pull down retracts.
17. The top status changes from CLOSED to OPEN.

The sequence for closing the folding top is as follows:

1. Hold the open/close control switch in the CLOSE request position.
2. The folding top status changes to closing.
3. A message is sent to disable the windows from operating using the door switches.
4. The windows open using the express open mode.
5. A class 2 message is sent to the BCM to unlatch the folding top cover.
6. The BCM sends folding top cover latch ajar message via class 2 serial data line.
7. The folding top cover opens.
8. The folding top cover pull down striker is extended.
9. The BCM sends folding top cover pull down ajar message via class 2 serial data line.
10. The top closes.
11. The 1 bow and 5 bow are raised.
12. The folding top cover closes.
13. The folding top cover pull down retracts.
14. The 1 bow and 5 bow are lowered.
15. Manually latch the header. The FTC module reads that the pin receiver switch is Active.
16. The top status changes from Open to Closed and a chime tone is heard.
17. The windows are enabled.
18. Raise the windows using the Express up mode, by releasing and pressing the open/close control switch within 5 seconds of the top being secured in the closed position.

Hydraulic Control

The folding top control (FTC) module also controls the hydraulic system used to operate the folding top by controlling the On/Off state and direction of the hydraulic pump motor, and the open/closed state of each of the valves in the system. The FTC module has the ability to operate the hydraulic pump and all three valves simultaneously and independently. The three valves controlled by the FTC module move the following components:
The folding top cover is controlled by the pump by-pass valve located at the hydraulic reservoir. The direction of the tonneau movement is based on the motor direction.
Whenever the open/close control switch is released or the top becomes inoperative in a suspended state, pressure will be maintained in the system to avoid drifting and damage of components. After 4 minutes, the FTC module will release the hydraulic pressure by cycling the valves ON and OFF. This allows the top to gradually settle to a resting position.